The Reuters news agency has said it did not mean to edit out a dagger and a pool of blood from photographs of Israeli soldiers injured on the Gaza flotilla.
In one of the original images a pro-Palestinian activist is pictured pointing a knife next to a wounded Israeli soldier.
But when Reuters distributed it, the photograph had been cropped so that his assailant was not visible.
A second picture, showing a soldier being held down by an activist, had been edited to remove a pool of blood and a dagger from the scene.
The images, distributed by the Turkish media, had been released in full by the Associated Press but Reuters only did so after a blogger pointed out the unusual editing.
“One picture cropped to remove a knife might be explained as incompetence or a simple mistake. But now we have two pictures, ” wrote the blogger, Little Green Footballs.
A Reuters spokesperson said the decision to crop the photographs had been “inadvertent” and that the company was committed to accurate and impartial reporting.
The spokesperson said: "All images that pass over our wire follow a strict editorial evaluation and selection process.
“The images in question were made available in Istanbul, and following normal editorial practice were prepared for dissemination which included cropping at the edges.
“When we realized that a dagger was inadvertently cropped from the images, Reuters immediately moved the original set as well."
In 2006 Reuters faced criticism for adding smoke to a picture take during the Second Lebanon War.
The activists on the Gaza-bound Mavi Marmara have claimed they were on a peaceful humanitarian mission, but video footage shows knives and other weapons were found on board.